While more than half of Americans have favorable opinions about self-driving vehicles, most believe that humans are still better drivers than automated technology, say University of Michigan researchers.

The same goes for those in Australia and the United Kingdom, although residents there are less concerned about safety, security and privacy issues associated with autonomous vehicles.

Brandon Schoettle and Michael Sivak of the U-M Transportation Research Institute surveyed more than 1,500 American, Australian and British residents about their views regarding limited and completely self-driving vehicles.

They found that roughly 57 percent of respondents from all three countries have positive opinions about automated technology in vehicles (compared to about 14 percent with negative views) and a majority have high expectations about its benefits. More than 70 percent believe that self-driving vehicles will result in fewer crashes, reduced severity of crashes and better fuel economy.

Even still, nearly three-fourths of Americans and two-thirds of Australians and British are moderately or very concerned about self-driving vehicle performance compared to human drivers. More than three-fourths of all respondents are very or moderately concerned about the safety consequences of equipment or system failure and about fully autonomous vehicles getting confused by unexpected situations.

In addition, roughly two-thirds are very or moderately concerned about system and vehicle security (from hackers), data privacy (location and destination tracking), system performance in poor weather, and interacting with other vehicles, pedestrians and bicyclists.

Despite high levels of concern with self-driving technology, about two-thirds of the survey respondents say they are at least slightly, if not very, interested in owning and/or driving autonomous vehicles. Although a majority are not willing to pay extra for the technology, a quarter of Americans said they would pay at least $2,000 extra, while a quarter of Australians and British would pay at least $2,350 and $1,710, respectively.

"Motorists and the general public in all three countries surveyed, while expressing high levels of concern about riding in vehicles equipped with this technology, feel positive about self-driving vehicles, have optimistic expectations of the benefits and generally desire self-driving vehicle technology when it becomes available," Schoettle said.